Patent Document 1 discloses a conventional overturn preventing device. This overturn preventing device is mounted between a top surface of a piece of furniture installed on a floor surface and a ceiling. The overturn preventing device includes a support pillar with a built-in spring and first and second base portions having shafts inserted into both ends of the support pillar respectively. At least one of the first and second base portions is axially movable forward and backward. The spring applies an elastic force to the first and/or second base portion in a direction such that the length of the overturn preventing device is increased. The overturn preventing device is mounted between the top surface of the furniture and the ceiling so that an axis line thereof extends in a vertical direction. As a result, the overturn preventing device can prevent the furniture from being overturned due to quakes of earthquake or the like.
Furthermore, the inventors have found that the furniture can effectively be prevented from being overturned in a case where the axis line of the support pillar with respect to a vertical direction is inclined at an angle ranging from 15° (equal to or larger than 15°) to 25° (equal to or smaller than 25°).